Physiological Demands of a Simulated BMX Competition

Description

The aim of the present study was to investigate the physiological demands of Supercross BMX during a simulated competition in elite athletes. During a preliminary session athletes underwent an incremental cycling test to determine maximal oxygen uptake (VO 2max) and power at ventilatory thresholds. In a second phase, athletes performed alone a simulated competition, consisting of six races separated by 30 minutes of passive recovery on an actual BMX track. During this simulated competition, oxygen uptake, blood lactate, anion gap and base excess (BE) were measured. Results indicated that a simulated BMX competition induces in elite athletes a high solicitation of both aerobic (mean peak VO 2 (VO 2peak): 94.3 ± 1.2 % VO 2max) and anaerobic glycolysis (mean blood lactate: 14.5 ± 4. 5 mmol.L-1) during every race. Furthermore, the repetition of six races separated by 30 min of recovery led to a significant impairment of the acid-base balance from the third to the sixth race (mean decrease in BE:-18.8 ± 7.5 %, p<0.05). A significant relationship was found between the decrease in BE and VO 2peak (r =-0.73, p<0.05). These findings confirm the importance of anaerobic conditioning in BMX athletes, and highlight the importance of the oxidative pathway in this sport where repeated high-intensity efforts are required.

Abstract

International audience

Additional details